NEIL Harris was left counting the cost of poor refereeing decisions that left Millwall returning to London empty-handed after another Tuesday night defeat.
The Millwall manager was particularly aggrieved with the decision to give Mark Beevers a second yellow card for a foul on goalkeeper Jon McLaughlin in injury time.
Referee Oliver Langford also failed to award a second-half penalty to the Lions, despite admitting there was contact on Aiden O'Brien in the Burton box.
"That gets another goal and at least a point if not go on and win," Harris said. "I felt really harshly done by with the refereeing decisions tonight and I think that's the first time I've said that as Millwall manager.
"The sending off, Beevs says he hasn't touched him. Obviously I'm not blaming the goalkeeper but Mark's looking at the ball the whole time and I don't know how he can avoid the player, to be honest.
"Anyone who knows Mark Beevers knows he's one of the calmest players you'll come across. Malicious? Definitely not, so that's a frustration."
Harris, however, didn't spare his players from criticism after Burton scored their first goal from a set-piece and added a second on the break moments after Millwall had lost possession on the edge of the home side's box.
He added: "I just said to the players, as good and as dominant as we were in the second half you just can't give two poor goals away.
"You can't give away goals away from home like the two we conceded at Fleetwood last week, which were really poor, and the two (Tuesday) were also really poor. We've got to get out of that habit because it's unprofessional and the mindset of the players has to be better. I'm not here to praise anyone after a defeat."